It is well known in the electrical connector art to use terminal pins for interconnection with female terminals, for insertion into holes in printed circuit boards or for other applications as connector contact components. The pins may have rectangular/square or round cross-sections and typically are made with a pin core of an electrically conductive material which is plated with a conductive layer different from the core in order to reduce the cost of the pin and/or to provide a more rigid core than the more pliable conductive layer. In addition, the layer conventionally will not oxidize as much as the core. For instance, a pin core may be made of such materials as copper, brass, or suitable alloys, and the outer conductive layer may be made of such materials as gold, silver, tin, nickel, or a suitable alloy. Such terminal pins have been fabricated both by post-plating as well as by pre-plating the pin cores with conductive layers. The terminals often are fabricated with pin tips having flat tapered sides to facilitate alignment with a mating female terminal and/or for insertion into a plated-through hole in a printed circuit board. Post-plated pins are relatively expensive because the post-plating procedure requires additional steps, time and material, and there is a tendency for the pins to be become bent or otherwise damaged during the additional handling for the post-plating processes.
Pre-plated pins which are swaged or coined to produce the flat tapered sides of the pin tips result in sharp edges which may cut into a mating female terminal or in a plated-through hole in a printed circuit board. Also these pins may not have a sufficient amount of plating on the pin tip to prevent corrosion build up.
Still other such terminal pins are fabricated in an in-line process where the output includes a line of pins connected tip-to-tip. The adjacent tips are severed to form individual terminal pins, but the severing creates a substantially flat non-plated tip surface which also may form sharp edges. Like the sharp corners of the flat side edges of the pin tips, the sharp end edges may have to be removed by still additional fabricating steps or processes.
While most terminal pins heretofore available and as described above have performed satisfactorily for their intended purposes of electrical conduction in various electrical connectors, there still is a need for a relatively inexpensive terminal pin which solves the problems identified above, particularly the problems created by sharp edges on the pin tips of the terminal pins.